The Quality of Life of Mustard Gas Victims: A Systematic Review.

Background
Today, a host of veterans who were exposed to mustard gas suffer from substantially poor quality of life (QoL). However, factors that influence these patients' QoL have not been yet scrutinized. QoL is deemed as a crucial construct that demands careful attention during evaluation as well as intervention. The present study aimed to delve into the physical, mental, and social factors that affect the QoL of mustard gas victims.


Materials and Methods
All the physical, mental, and social parameters that influence the QoL of mustard gas victims were scrutinized through a systematic review. We searched for Persian and English scientific databases, i.e., PubMed, Scopus, and Google Scholar, and national databanks, namely SID, IranMedex, and Magiran to identify studies related to chemical victims conducted up to the end of 2015. Next, the quality of 21 articles and studies were assessed using the checklist of the National Institute of Health (NIH), and subsequently, 13 articles were selected for the stages of data extraction and analysis.


Results
Findings revealed that, among the physical factors, coexistence of several medical conditions caused by chemical injury and the severity of the chemical injury had the greatest impact on the QoL of chemically injured veterans. Besides, suffering from psychological and neurological disorders, along with educational level and employment status, were the most influential psychosocial parameters that influenced veterans' QoL.


Conclusion
The review conducted herein identified the physical and psychosocial factors affecting the QoL of mustard gas victims. In fact, it is the first to present a large collection of descriptive information on QoL contributors in a systematic and orderly fashion.

chronic phase symptoms and signs highly impact the QoL of victims (8). Brain damage or severe organ injuries can influence the mental health of victims, which may be accompanied by familial, social, and even economic problems (9,10).
According to different studies, chemical victims' QoL scores were lower as compared to those of normal civilians (11). Research and therapeutic approaches to chemical victims' complications are different from the approaches to other conventional lung diseases (12).
Despite the positive effects of standard therapeutic protocols that are used for usual lung diseases such as asthma and COPD, such procedures are not suitable for chemically injured victims because of the fast emerging side effects. Thus, as lung exposure to mustard gas does not fit the signs and symptoms of any specific disease, it was named as "Mustard Lung" (13). This phrase uniquely represents the specific nature of such lung symptoms (14).
Similarly, the QoL of such patients involves different and exceptional aspects according to altered signs and therapies. Therefore, we coined the term "Mustard Quality of Life (MQoL)." In this regard, improving the QoL of chemically injured veterans ought to be synched with the specific and unique nature of the morbidity, based not only on the physical, but also on the spiritual, psychological, cultural, social, familial, and economic aspects of QoL (15).

Study design
This systematic review was conducted according to the guidelines of the Center for Reviews and Dissemination, York University (16). All studies pertaining to QoL of people who were injured by sulfur mustard were examined carefully. As specified in the guidelines, the review comprised the following procedural elements: 1) the review question, 2) strategy to search databases, 3) inclusion criteria for studies, 4) tools for quality assessment and study appraisal, 5) study selection based on eligibility, 6) data extraction and analysis, and 7) data synthesis.
To identify other systematic reviews with objectives similar to those of the current study, the Cochrane The keywords "chemical veterans," "chemical warfare," "chemical warfare agents," "chemical weapon," "chemical injuries," "quality of life," "mustard," and "mustard gas" were searched in Scientific Information Database (SID), . Here, studies that did not clearly satisfy the inclusion criteria were excluded from the systematic review. On completion of this preliminary assessment, the full text of the remaining articles was retrieved so that the referees would perform eligibility assessment once more. Those articles that were subjects of controversy between the referees were referred to a senior scholar (AE) to judge their eligibility.

Quality assessment
In this study, the studies that could answer the present research question were examined. These articles underwent a critical assessment via a checklist provided by the National Institute of Health (NIH). The checklist comprises 14 items for the quality assessment of articles (18), which was later modified in accordance with the research objectives and question, as well as the instructions of York University. After the quality assessment, articles obtaining 60% of the total score were subjected to subsequent analysis.
In this step, the required data on the dimensions of QoL and its influential factors among mustard gas victims were extracted. The data included demographic characteristics, chemical injury-related characteristics, instruments, educational level, and physical as well as psychosocial dimensions affecting the QoL of mustard gas victims.

RESULTS
The current systematic review constituted the four main stages of identification, screening, quality assessment, and analysis (16). In the first stage, searching In the third stage, full-text versions of the remaining articles were retrieved to assess their eligibility. Thus, 56 articles that did not meet the necessary requirements were excluded from the systematic review. Accordingly, 21 eligible studies that conformed to the present research question and met the inclusion criteria were subjected to through quality assessment using the checklist developed by NIH. The quality assessment revealed that 4 articles did not have the essential data related to the current research question or did not employ the cross-sectional design. Four other articles failed to achieve the minimum required score on the checklist. Therefore, only 13 articles were used for the subsequent stages of data extraction and analysis.
Besides, to gather additional facts and details needed for the current study, the review team communicated with the corresponding authors of two articles.

Included studies
Data regarding demographic and chemical injuryrelated characteristics ( people. In addition, information on "educational level" was provided in 10 articles, on "employment status" in 9 articles, on "rate of chemical injury" in 4 articles, on "mean time since last exposure" in All included articles reported low QoL scores for the mustard gas victims, and several subjects exhibited an extremely poor level of QoL (20)(21)(22)25). Some articles also compared the QoL of mustard gas victims with that of the general population, which revealed a low QoL level among mustard gas victims (20)(21)(22)30). Further, the studies revealed that mustard gas victims experienced further problems in some QoL subscales, i.e., mental health (15,21,29), symptoms and activities(23, 25,26), general health, and physical functioning.

Physical factors and QoL of mustard gas victims
Among physical factors influencing the QoL of mustard gas victims, concurrent existence of pulmonary, ocular, dermal, and psychiatric complications had the most damaging impact on the QoL of these patients (15,19,25,26,29). The severity of chemical injury was also a factor that could considerably exacerbate the QoL of chemically injured veterans (23-25, 30), though several studies (19,26,29) refuted such a relationship. Besides, some studies suggested that a low level of physical health could account for decline in life quality (19,27,29). Accordingly, a number of studies reported that participation in sports activities could be an influential factor in improving the QoL of exposed veterans (20,21). The persistence of complications due to chemical exposure was the other parameter described in two studies, which impaired the QoL of mustard gas victims (20,29
Finally, Jafari et al. (21) reported that increase in the number of children could influence QoL, while a study by Biat Saeed et al. (29) refuted such a connection.

DISCUSSION
Several chemically injured veterans suffer from a poor level of QoL though it has been 30 years since the first exposure to mustard gas (32). Therefore, the current systematic review aimed to determine the physical and psychosocial factors that affect the QoL of mustard gas victims. To our knowledge, this was the first systematic review that investigated the QoL of mustard gas attack survivors.
Thus far, there have been several attempts to gather comprehensive information on the life experiences of exposed veterans, but such studies have failed to develop a decisive and well-rounded protocol for planning clinical care and psychological services for chemically injured veterans. The current systematic aimed to lay foundations for research and psychosocial intervention to improve the QoL of exposed veterans.
Given that mustard gas victims experience particularly distinct aspects of life and they have to deal special problems, it is important to consider diagnoses and care plans fitting their condition (12).
Mustard gas victims sustain several medical conditions (pulmonary, dermal, ocular, neurological, and gastrointestinal disorders) in addition to psychiatric distress. Therefore, their QoL can be assessed from different aspects. Such a multi-dimensional nature also entails using specific instruments that are only designed for mustard gas victims. Considering these factors, major improvements in the QoL of exposed veterans can be achieved by taking small steps to change their lifestyle (33).
The results of the current systematic review also The current systematic review indicated that, among the physical factors affecting the QoL of mustard gas victims, the most frequently identified influence was the co-existence of several diseases such as pulmonary, dermal, ocular, and psychiatric complications (15,19,25,26,29). This factor was followed by the severity of chemical injury, poor physical health, and pulmonary problems, respectively. In fact, a low level of physical health, as reported in several studies (19,27,29), along with suffering from long-term complications of mustard gas (35,36), can be deemed as the most influential factor lowering the QoL of exposed veterans. Several studies heavily stressed that the co-occurrence of several diseases; other factors such as aging (21,29), long persistence of mustard gas complications (20,29); and severity of chemical injury, together with the number of damaged organs (23- 25,30) can largely impact the QoL of chemically injured veterans.
As these patients face several physical problems, they usually suffer from poor physical functioning as well (20,22), which often leads to obesity and diabetes, and consequently, results in the reduction of QoL (21,37).
Furthermore, findings of the included studies showed that the long-term complications of mustard gas increased the risk of developing cancer (15,19). Recent studies also highlighted the risk of cancer due to mustard gas even years after exposure (38)(39)(40). Results of a study by Ghanei et al. reflected that pseudo-cancerous symptoms that may occur due to brief exposure to mustard gas still heightened the risk of cancer in exposed veterans (39). A cohort study by Zafarghandi et al. also indicated that the prevalence of cancer among those exposed to mustard gas was remarkably high (40). Further, cancer patients who are treated using mustard compounds ultimately develop secondary malignant growths like Leukemia and Lymphoma (12,41). Studies on cancer also suggest that the QoL of cancer patients drastically decreases during the course of the illness (42). As a result, exposed veterans' QoL is impaired, first by the late complications of the chemical agent, and then by the fear of developing cancer (15,19).
However, plans to psychosocially support these patients can favorably influence their QoL, as well as that of their families (43).
It is probable that the sample group suffered from impaired QoL due to physical and mental disorders (35,36,44), as well as due to problems such as having a history of hospitalization for psychiatric complications or taking psychiatric medication (26), poor emotional functioning (19,22), low level of mood and emotions (28) (47). When these symptoms appear, in most situations, they provoke negative feedbacks and finally lead to social isolation, depression, anxiety, sleep disorders, and disturbances of interpersonal relationships among exposed veterans (48). Thus, when mustard gas complications occur over a long period, patients often exhibit aggression, anger, and reluctance to engage in social interactions, which together impair their QoL (49).
However, recent studies strongly emphasize on the importance of social support for treating the mental and even physical complications of chemically injured veterans (43,50).
In most studies, a high level of education was reported to have a positive influence on the QoL of injured veterans.
This may be explained by the fact that the increase in knowledge about methods of symptoms control, together with rise in social interactions, may help improve QoL (20,21,29). Moreover, employment and economic problems stemming from medical expenses played key roles in the QoL of mustard gas victims (15,22), in addition to several other problems, particularly the lack of daily activities. It is also notable that health care costs constituted a major item of their expenditure (51,52). Generally, it has been reported that mustard gas victims can hardly handle personal affairs and almost all had problems related to managing living costs(22, 51) because they not only sustained physical disorders, i.e., pulmonary (21,53), dermal (28,46), and ocular(22) complications, but they also experienced fatigue (54,55), sleep disturbances(56) and adjustment disorders (44). Further, they suffered from mental diseases, e.g., depression, anxiety, and PTSD (10,35,(57)(58)(59).
Abbasi (15) reported that exposed veterans often encountered unsuitable income level, employment status, and dwelling place. This explains why veterans with an appropriate job enjoyed superior QoL, as employment substantially improves the QoL of mustard victims (21,25,26,29,30). Inability to afford living costs can lead to physical and mental complications, and in turn, impair QoL (27,60). However, in sum, it is clear that most studies have failed to suggest a holistic approach to intervention.
In fact, given their special physical and psychosocial conditions, exposed veterans need comprehensive plans and measures to enhance their QoL.
One of the constraints that the current review encountered was that though the studies scrutinized herein contained a huge mass of data on veterans' QoL, some pieces of information, such as mean time since last exposure, frequency of exposure, and severity of chemical injury were neglected. Hence, this study recommends that prospective studies should make use of specific instruments to evaluate the QoL of mustard gas victims and should address the above-mentioned variables.

CONCLUSION
The analysis conducted within this review backs up the theories on the impact of physical and psychosocial factors on the QoL of exposed veterans. The findings suggest that the coexistence of several medical conditions caused by the chemical injury, severity of chemical injury, psychological and neurological complications, educational level, and employment status and job-appropriateness had the greatest impact on the QoL of mustard gas victims.
Nevertheless, long-term studies are required to determine the correlation between veterans' QoL and these physical and psychosocial parameters. In future, research should focus on improving the QoL of these patients by assembling a multi-disciplinary medical team.